SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '688efdbaf08b0f35097e453dcb59648ecd75e6a382fcc71bc8e47e317d7741bd' 
  AND token = 'Ygf3FCQ+kmkOKuqoS+zBsE9v6mi6/u4g1ZYTpNFnL4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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