SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99d13256b5284413f2ee27c2d1eed1a4c6743a260180dd76c39f295e31e184a1' 
  AND token = 'iZIWr0VKTRvx3SNM54fpmyvoa9fyBenzIKSt6UPbBUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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