SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac2b269aed85d947eedb92aad3566cd424863ec1776a4004c4e453dad8ca065' 
  AND token = 'xdJ8XUS8GOPVcuyxPBA09lETq1rENUFqSzD5AwypJTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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