SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81eccf3caad15b9b90cb6a45dc32da617c733bf13b67e9ec0d78255083bd615d' 
  AND token = 'W7FfB70c5yuEN/L0u+CkNLd/lVAy1NEy6mtMIV1mQ9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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