SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c59f9af60bcd1fd6f877db6ec552154739293e57a678b5be069bc6de72d19fd' 
  AND token = 'A5EaxDlw2zqIuFloEdpv0tLi8KHb3QlQG4lhf5XpAiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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