SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb3afe0e00bbcd5f8661dd6aba32cafafd999fd0396b74f92fa85de4dff6739d' 
  AND token = 'SNLkhIW2tCUKvrgh626nQ7i3gYFrae9bAZHOKP80qBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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