SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '675689507722b9e1a024759791cfdd8fcc3934f80027ead0bf11c027acc96efd' 
  AND token = 'AV3wmEyyxB/yjUMihzMtIHI6mHR3ip5zCagfZlM6w8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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