SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11ac1ef8f9e1f9f9bb225dc948a918e37774e39b19b021c2597746a76e181598' 
  AND token = 'JwlTOy9JuhX9D419rxvMxI27T2w2XF5zr6MRgwl+4E0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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