SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f89be9e781ca1b7fc817514e9abd4b73f63223f8a96749af616cbbe300184a8b' 
  AND token = '+oVejjVrJhD27oaAAZbmR/ggtGwWRo7vxqxDcuz1RlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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