SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d5b6d951fc6715cc44a41a615a2d04e06b5732cf92a0ff0c52d850cabcd0c22' 
  AND token = 'AkzKRhTJ1rKtA6GhtDr4ZH6KXgDD8EfJz+nkUToZCus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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