SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7d3e125c4d854a688d11912c536aaf31dc03666d5d2c989ad823818314acf1e' 
  AND token = 'Mlpt/xAH9uvkNhMi563bAbp24NbVx6V2cAEbJ1xMkUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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