SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7368120710152db335dcde21452f1b774ff68dedd58333c2e88eeb97922f9f2a' 
  AND token = 'eH7fZTixepx6l3SJi5Fy0A7Bb8kVXSsV+2Hq6cOYPcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}