SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3f3b5bc64830864c78ca3d6da2583f187cf3efc35b423657349a24ad13fe045' 
  AND token = 'Hw0jA21DZs2fzXvz3S/zIr+3TY4qUPQunGrTRp+HbG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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