SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e506112b7dcd368e59985e9c82095d3034b9c6fef8b0ab2483de840c7407694d' 
  AND token = 'X17qWIoTTnmxw/E02GYIyBOjOXFCdqqrcPCRZfhmrbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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