SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e920edc3d9848f89009bcd9c994910774c5b772ad2bfb3c3d6d99739873a8ae' 
  AND token = 'utCe/3ByzCGYZXaT6WHeUlAOrjAaI6Pxx5fafV98ZHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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