SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f360660d2906dfc00e946b92f5d7258677c867d6ccf57a2307299af60059a05' 
  AND token = 'A1LCEjQ09qQGC63rhlVpjRBPYzfZn2Kv3dD//YGmM3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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