SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '044639928a8823c06c4748319babd1a8f4dd688a7f33951de4641ab9b3b070fa' 
  AND token = 'i3ispCfTOz5Zrc3ANVZ0xlSJs2ZnWa1Ly8Oor7Yqa/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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