SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9030a57b80a3f45e6d848e58485e0f467bd13f483146542e02bc020a7de1791f' 
  AND token = 'riadvGbUdrn7kZGPE48Fw6eXJV5lDzVE3rbgqWPQsIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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