SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcb1d70771df0d55c6529698d99725816ba77ce1e93746d72cdc69346568a0c2' 
  AND token = 'kc0BWB4zPQVxvdpVrM8jnIhxnGuc89jbpgXMIZ9xp/Y=' 
  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"
    }
  }
}