SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daa645aadc9631692b6073158d7741c6c8457c2f98f649753ac09e7cd0dd723c' 
  AND token = 'hHoWmj/aJmgXGzGRAZV+cB8evcT/iw7HRfZXUf3VECM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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