SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55e7e1721306b649c3d35c8e8a415d60ecdb305ecc3d2ff06ad4cc008f5401b2' 
  AND token = 'u3ZNTL6unsk3JnCZ+siO+TwMWNvHy1yQfvnGSxJXogo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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