SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dec0cbdbbdd7631ab8825cf1a95b2b306335eef36079bf80be50be539335476' 
  AND token = 'NIOKwg6spmKVLJ6PjSM06I4wtLMDYzBGmvDW9xYupAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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