SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b87f875a66eb5b54b06de0e11a600ebda9a3bd228f03b84977c4ca8fe1e148e' 
  AND token = 'lGHIFEBeLzmi6OngieC19dRExl/XAVO/ESESTWrS2fU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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