SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17883c7ed59bad8ca63faad73594b9efb8d7196cf778cf04e1e60b1053b2afc4' 
  AND token = 'PFRJRIwy5hDlOXJIAHruvTQEm0/Zt6ZrRkY/pmcoO78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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