SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1e8f7e38918c7bcb45ec5652e644f9a4d5c2e4c23485f6e3359369f54698318' 
  AND token = 'GRFsDShA96yRb8yZnK2spw0PrV4WPQu1O9uhoTuXaXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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