SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a60e3542a6eb4a1de3ce755555382f14ffa4de5079380696ff7923d32986e17' 
  AND token = 'TdOvgQH98MczLOZIoXo0UTxSJBDCblnKNHxQl+0ZV6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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