SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83f20475846bc9fc147b37af42a40648ff5ec218f0a1e00bed19232eff9779cc' 
  AND token = 'G0XGrAIdP/LAxopCVvoF5jLE6kjUnqNRR06/ZKgkSlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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