SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dad972b95741e3383fe4557cd45539d390a7f8f817ef1abe148a19c9a4ae584b' 
  AND token = 'QYRlf3OAGAPPWhDD7U1VMdjtUIfXvVLsDquHT0k07Ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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