SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79102eb8744607b64b2d486c7bb0b6ec815c0e7ec8f2518367e51af7705ccce4' 
  AND token = 'UJsUO3SAwZlmvF2fXvTsrbxBYB1qBvDS2hrMqZqjcqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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