SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03a920da71b865f5c38535a98eb75bbd5257a92766c7bc7819ea02d33c2b12d3' 
  AND token = 'zAHUCNiRQuopJFd8hhDYvgYvb4YBUqs/Gn4D0rgYO8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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