SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ac950142a76b3192e2fe24cc5d88404e31e4cb1cd4a734d764751ee91c3ada3' 
  AND token = 'dT1AGiniGFf6fkk7TFqzXZL8KxoN24sUx6Q0m218Y8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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