SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a218fee808236985f67a9233fcf32c6abb78c65d8747a1c9d213361cfb04658' 
  AND token = 'xox+iZ5wXmJ5Tx2qbsFOAnTt5qNFPKuvvSlc2/kEj1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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