SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c5b346e57b0ee91320862ed3bf85ac951214e3497cbd7aed25f87a7e8d6a6c2' 
  AND token = 'ajR7ihVswKolK3rZ8AT0uOXEeAr2Wg1uLAcN6TlO89Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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