SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d3828f3f113b2d52556d34bd4235973893eb62fe254b44c2a05e66ba878184e' 
  AND token = 'zY0CTMZatNOYFQHAcGwZn/JRsOqwnkZMsCOmuXK4CuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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