SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '300ba283ddc7c084b7c9470f3bd8b22e151a26aa98437be1eda3dc7f044ab97b' 
  AND token = 'Wj/0emBnDXGEfB7Cqew/T/eySMUVMonJvuxgNzhrbSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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