SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2344bec2e658a4c29366eec6674814933f10d6d3f47bd6ca795549485df5192f' 
  AND token = 'CyOmcCbzHtyPGIA7CgjJJBbPX1svKSoKU8LkZneuAY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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