SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b7dbe483bf2f573b635bb54be8084b8625b49a9f321b8e4870fa99db4e4d76e' 
  AND token = 'cca7cw0pRQsWmcZU2JPZBxPLrPYgOzjrY+aSnylZhaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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