SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83acaac8f7a19389bdf1c424239aaff94723f2454926337edf09b8deef9090d6' 
  AND token = 'skfK7QzbAnZOBUJQX/40vo3lP8ZqktJpKt4aAVvpdQg=' 
  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"
    }
  }
}