SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '636aadf93383298e77a08080dd900f3e1d05ea83b7da0e207b7edc0632660c84' 
  AND token = 'efRn4uSmN1PAlVXkf/DrKHjXfOU5H72Ea9I7Ng73ol8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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