SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '681e4e873330ec206fdc8768e951b9091870df04594c9f7f79ba19389170cf4b' 
  AND token = 'dRQTHC6QVQTzmV4JKZDvnkrsYBLVnnHUhgUs0A7g0AU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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