SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3eaf4accc3c139354337ef07c2c63d78d37894690b827fcb4e7757f147fcc06' 
  AND token = '1kDXKCt4kwlee8yA5/WUvWMfeAuHlBZLVZ1W3pQbSbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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