SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6830d8c0f21113a43498702822c5711358b5116e06ad0568ea9ed3b4739175b5' 
  AND token = 'yEFpvw9vY+zvKqJpcq5RIQXmjQ882FeR/Ds4nzyr7HE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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