SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf85f1c3199cdee4f752368251ae6cb60cc2e34803e69556f6501de86f4b7cb2' 
  AND token = 'D8l6KmPPV5LPPmoSAC6JLqj5iDtcYyZUIbnrvcF4ZaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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