SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a19927d43120792137e4338ea5ee04e8561e880e538f95b21c54669f861a63' 
  AND token = 'YJd/wq5ZiKwreCthfvuxGlpoP/o5gausrrZKSR9C/Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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