SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f9a2418d43860e6ee6e2357603fb48aa670e3c294b8188c68febad18f01124e' 
  AND token = 'LnRqgT2Xpy5k9oBd1vdPwo2UGmi/l27WFADfDqZsgvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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