SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c93f874b5c00728f365795652d6fcd057f20ecbb3c26b7f809c22e28fdb776c4' 
  AND token = 'gMKCPDcTweirEiHwsHGBLizxm96JsTLAiSNC+sk+jgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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