SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9668872aeca436fd6b1577a4cf0de23462d94e3496d9bef28c4ba89d3aacc2b' 
  AND token = 'VFCuPkjW3f/oGVbDj+SSu649lSptgjHU3CY6Ic7T1bM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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