SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c34536ade617f72ab65901031e56384ad475f6238dce95a9931801955af8de0' 
  AND token = 'G2ANCLI2qEigZ451KX0bvEUmez41Y9xVL1jN0oKSbIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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