SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f3d607e7f303dc020e72c5f2be5287b27ba5eedb515f93178163f1db3e71483' 
  AND token = 'W6NVQy3YNrOObkmpjPu6DRC2eVQS1IYcqUuIh66vw8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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