SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1042a40566ced8a76b316a3f6dff84ed96dc0570a857dce527102599a1d5e01d' 
  AND token = 'bLcsb6jAltiQRWV+IJNnZ0/RZA7vFWS34uV9h5A/3NQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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