SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '775844f109d6ba045804e8433d5930af99c737d3c7c1401c7e05584a20303b19' 
  AND token = 'QN4UF4UTzHjnR29rMEZh6vvBHlGCLu/NmU0Yp65V/J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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