SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abcb5295d110bc119cc8fea4ae3b64a4954df010bb341e21751b3359adf4a55e' 
  AND token = 'RM2eU9CDMJnsgLeiC6kqNw72tDribLXluIbaeGTGTB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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