SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aceb73b08dd6f10c914faadb32f83b24636d34cdcfc6192d8318d1240cd377af' 
  AND token = 'ol5L9X2BDza+QFLJ4J2AYwNMnRAmzXY3MMwNxqrKhs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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