SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01614469658ed0a980fade8a2209cf3d01fd87d1f2c041e7d753796bb44dabff' 
  AND token = 'J6UAzBkMZ8rGCUo37MrQhV1rT2EG+v58d221cdRVUIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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