SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027bd886a9acc09ace69c0877ef5e4efdb1fb4b5bc61a109a8363de79b3e0214' 
  AND token = 'VF+OoCu/qsTfpm4skcbfPntGL9pcE3lSjD1wPVz00K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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