SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '844f5ee2fdb769e091d7195d22afcb53085d72d9b418f673ad8d0304a114c87f' 
  AND token = 'E8m2qqat1lFN3sc7r1G+IKFAskdeOmrXMrX9sjSgJ+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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