SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4347d3b2d4c136f90438a492d8131da635278f962c4761a9b1fb6ce05e948fd4' 
  AND token = 'X2GZ89OIZVMm91wVXyY8TAxQ+3RdprQ9w+ueqfsWj7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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