SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93f31f53f445161ca10f0e69f6fc5890f1060520ca9f3521a20be640ea39fa2f' 
  AND token = 'XXuqzL1KTGzBLlofZAuNAk9IT1dw3YlWqBlLy60fRts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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