SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '090eae9f2c7c8d18776a25e5ca48d26302dfec1c13ea312985ce671a60313206' 
  AND token = 'tyrK6wA+lrWs60RSpTlYCmi6ymvSd0ugSt4hPjhogj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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