SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7f9d7909f1b1cce3479a13bc5722636bdade7a2c197ad22db1f2000941e90f4' 
  AND token = 'b2+L5lA4mLNnhejq9SEtigHI35CMdyk3zosG7cXhacM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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