SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '433bad9a79dee110e789ef29415c39517af82d31024d62b3e56a89baec2471d4' 
  AND token = 'yJ/aESdVhLumMCVeR6NPKYM3pBjMMj6YlZRmjozK0xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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