SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d04766ec8dd46abeb517cc11b28b1320d9da961da5a164e24eeab06fed3b673' 
  AND token = 'VWE8lMdolNcizI5VBeuSqIw0wEw9mw5ArsHGD3VF9o8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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