SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95b132eda9d58596645aa739c978b0f171b69c5f1e412ea064373a1934a82aa1' 
  AND token = '5EewMzOA+TB4KWZuEqkUmeyacINfuI6FBtmqjuZ2z2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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