SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36e68149466f502adf144adb53e1eaf0c752139ead9c42fd7d0dacc25e0d5561' 
  AND token = 'es5/WxMUV8AlOgYqyRNAS7o4hUO8hPE3Nn7zMuaYuzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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