SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '532e49d4c48ecbf37570c003dc4aae836e4cf0c58f502190d2b002c4149eb9f9' 
  AND token = 'pSdycBrnJE3XSaMu5O5lsY3B6FexNEjhiO3ibeEIvZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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