SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0504f30fdbb64e5595951ce1929f70869523bfbec9402e6346ad9bff68b4a7f7' 
  AND token = 'v6hCmz367RN/ZrXlQBHlMvTnpajwb3TErXO0qJKQmdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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