SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05cc4820ba9084392a24d357ca5263a53566e4c104dc6ca10953c596808e2f93' 
  AND token = 'PKyI2M66kRSOJSmAvKhPQzzXpDN+fxiuWODDr53GqLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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