SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cbedb157a60fd9bfab42bc1a2fb13471204be9dd53bcfe0e75cfb01b6ed5173' 
  AND token = 'BsUg8WnV8NDtIQZwYk5OuGAuQ4fAfHeGczjKeQBRKcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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