SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3f24f06e7b09d986bc49d91bbf5e5ca59d414b65fda369fbb076d8ccf4c0880' 
  AND token = 'R4gEd9s3bPxV1NmknCwqRglVQtBffEsAZiXOhAH5Y60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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