SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db7638a420de630dfd97c35cfa61edd20309bdeb92981fe4ae5b1e654516689a' 
  AND token = 'q15sCobcNlblE39d/gxqBo/lToo0qBtvzaa9c2CRQKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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