SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d0ca31698d782e6919291c26f7453df4113ff0a208971240aec8b5f50d90e2e' 
  AND token = 'gOvJ8fpJaDDHJDZ5XI2IKwOkVaWM5aOurGM9ZyMNP9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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