SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '67e6a4cd6ce2dc7e30a301bfe37246f7e13bdb56e3eabde3814dd45cbe0ee8f1' 
  AND token = 'qudyvWgA1TPoq3hHPNqHVgLiDUnVviJ6Khf/K20+nao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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