Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1837e4f34b78ad43e9faf5b3a252e6d43660a6428a847c48a1e2b4e698e2f8c' 
  AND token = 'MLn1cQHmoPZAxtYQKk1+U9B+fUcmHAfugINEN3dQAd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}