SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd37a806e375a9cc2e22510ed632660957bdee9540284bb501180537431e8021' 
  AND token = '+GXBBScNj8r/DDX2ah0BVfBwXFUbvNG1VsVkmfJTo0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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