SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aefebe62288c57830e6f64cab6dfb443c373d2add5138179c2d2c1980fe6554c' 
  AND token = '8I//UqrHnCajwQdvpV/fUyh03wuk38Oqo5CNuJoPajk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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