SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4a88690d7ca83a36460930558f5350f2011fdf1fcb29a72511d71508b26924a' 
  AND token = 'MGD9aopgfqzK0LbElpYx8QwoCUMz7UeJ62uDmeAB8/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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