SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c216773bb1686898f06522fb0006a8b83dd2458b51a2d1a2286ccf825dae672' 
  AND token = 'sxc9WdAEY8xvbC8IdUtjiGQdLcLv6DNNSSCkYdfJwF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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