SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a03df85098e1b1ded5cd23e18845f8d169244539a17e76a8ef8cb0fbc911d21f' 
  AND token = 'J46B8NgFMjSWrH8Ni8LG9mECDtVA2qIdhkTk9uUACHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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