SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83521daa870eeecd2e103de4d9e97a48c0b93ae250a29e73e08e7df0595b8f0e' 
  AND token = 'Iz/asgHkMhvplF0I2auZkVnUAgeKfqXPp+wAFkOjTUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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