SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fd0e6b4525766cd11471f2819bb672b74b30483836f58e71049690b9fdc5a4d' 
  AND token = 'pjDC+cRAapUk6MmtudJYm1Hy+XVprNSxGiaAqcTBHbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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