SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f171f980fcde1ddbbe8eb6a6f59b13dcefd1102e94f2e097e7b5262f6878357a' 
  AND token = 'PmPXRKzCwJERvznECXyyvYvbmcGrJSW4MsSGY4ZBzXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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