SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd57694bdc442e01a87d5d7a83c2e2c60f6305e653793bf12d2bbaeec63dc7483' 
  AND token = 'uxfGtA6px4lyP5Bgzbl/lzMYYQUwFTL+RzUcXBsWG4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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