SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dc177e37e2e0f996be865ebb31f9a949b43cb908f88b4d7a95766e595425781' 
  AND token = 'ngEjU72TvJtTR+eSTmwKBCJUofrdL2QjvurtDq/JWNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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