SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc1aa02bd865eaf8e1565668fe48320036352b37a32aab9ac9d5f2765851e5f3' 
  AND token = 'c2ppFRmpO3JXcTbbgI43qOfn9jxJzwYQ42Wu9N7adn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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