SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '888178ef3c0ac2c65f922b73da2aa73c1fb3b7acd4f1a85533ddf5358c9e6ba0' 
  AND token = '03bs7ntKU46yvhhld01Bj3eaUq0lKbWd2VaJib42XUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}