SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e13a23859bb1d72cb2b1a48325ac89aa58106e1472d36a541beffdf6aca73976' 
  AND token = '4eFfTOFM0P+17FN9UiZt2DeZ7pvy+NoGF/7jvV7HNoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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