SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bae71c6ef227790913ea47c88da653fc229091bd68f2b679681b803fd1510a67' 
  AND token = 'NCMHqqyrvIzjbigZ26DDMBcSN1qKdK2gFDIqAK64FQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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