SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9a5d754724d9218af2c901b654d2aaee4174c3e1427dc3534ae68593da41163' 
  AND token = 'rjvNbwI543ZA+Jizp/2ISCpwQPGriGb6Z01obokMX4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}